This pilot study will examine the acute and chronic effects of resistance exercise on insulin sensitivity in sedentary, middle-aged men and women. Insulin sensitivity will be assessed before training, 22-24 hours after a single exercise session, and again 22-24 hours after the last training session. The primary purpose of the protocol is to determine whether performing multiple (3) sets per training session is superior to performing just one (1) set with respect to improving insulin sensivity."